I recommend redeeming 400 codes per set to maximize your chances of completing the set and earning some valuable credits
These promo cards also come with a fancy first edition logo, letting collectors know that even if they Mickey Mouse for another event, theres only one printing that came first
If you want to get higher value cards, trade in stages
Listing is for the Japanese Edition
If you just want to stomp the game I think things are easiest with Squirtle and friends by far, since you can build it into a Rain Dance deck later and have something that's out of any of the CPU trainers' league, whereas Charizard and Venusaur aren't as competitively powerful(though Pokemon Center cheese with Venusaur is pretty entertaining...), but you can really get away with doing a decent version of whatever you feel like running so I'd just go with whatever you think sounds fun
When Yugi tries to return the card, Joey refuses, stating that Yugi rightfully won it and would need it for the Battle City Tournament